A radio access network (RAN) configuration has been changed such that various types of small cells such as a pico cell and a femto cell interact with a macro cell. The RAN configuration refers to a heterogeneous cell configuration or a hierarchical cell configuration in which small cells for low power/near field communication coexist in addition to an existing macro cell-based homogeneous network. An object of a new RAN configuration is to increase QoE (Quality of Experience) by providing a high data transfer rate to an end user.
In small cell enhancements for E-UTRA and E-UTRAN study item (SI) as one of 3rd generation partnership project (3GPP) standard scopes, research has been ongoing into enhancement of indoor/outdoor scenarios using low power nodes, and the scenarios is described in 3GPP TR 36.932. In small cell enhancements for E-UTRA and E-UTRAN SI, research has been conducted to draw advantages of concept of dual connectivity to small cell layers and a macro cell layer in which a user uses the same or different carriers.
When the aforementioned trends are considered, if various small cells are deployed, users become more physically closer to a network. Hence, in an enhanced 5G wireless access network, it is anticipated that communication will be performed not based on a cell of a legacy base station but based on a user-centered virtual zone. Moreover, in order to realize the communication based on the user-centered virtual zone, it is necessary to draw a service provision unit differentiated from a legacy cell-based service provision unit. In particular, it is necessary to draw and solve technical issues capable of implementing such a service provision unit as a user-centered zone and the service provision unit may cause a considerable change in a current wireless access network.